The referendum on whether to secede from Iraq is planned to be held in the three governorates that make up the Kurdish region, and in the areas that are disputed by the Kurdish and Iraqi governments but are currently under Kurdish military control.

The disputed areas include swaths of northern territory that are claimed by both Kurdish Iraq and Baghdad, including the key oil-rich province of Kirkuk.

‘Terrible mistake’

Opposition in Baghdad to Kurdish Iraq becoming independent would become even greater if the region tried to take disputed territory along with it.

Turkey also came out against the referendum on Friday, calling the plan a “terrible mistake”.

“The maintenance of Iraq’s territorial integrity and political unit is one of the fundamental principles of Turkey’s Iraq policy,” the foreign ministry said in a statement.

States that neighbour Iraq, including Turkey, as well as Syria and Iran, and which all have large and sometimes restive Kurdish populations, have in the past resisted moves towards Kurdish independence.